Simulations

The development of wind farm control algorithms requires a fast model to develop the controllers, and a high-fidelity model to verify them in realistic wind flow. The latter is done with Large Eddy Simulation, which is a complex but very realistic computer code run on supercomputers.

The problem here can be broken down in two: First, the computation of a realistic and self-consistent fully turbulent flow field, split up in different wind speeds and atmospheric conditions, and the flowing of this field over the wind farm. The first one is called a precursor, and needs quite heavy computations; the ones done by partner KU Leuven ran on 900 cores for 5-6 days.

The latter is much quicker to compute, which is why the process is divided in two. The precursors were calculated with the SP-Wind code of KU Leuven and the EllipSys3D code from DTU.

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The precursor fields are large enough to contain the virtual wind farm, here either the newly defined reference wind farm (white turbine locations) or the Lillgrund wind farm (black dots) which is used for the measurement campaign.

The precursors are described in a public deliverable, D1.4 Flow Database for Reference Wind Farm.

A subset of this dataset is also freely available on Zenodo. [INSERT LINK]

Reference wind farms

Four partners worked together to first, find other possible candidates for a reference wind farm on which to develop and try out the control algorithms, and second, developed their own reference farm.

The project uses the IEA reference wind farm and the new layout:

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Layout of the TotalControl Reference Wind Power Plant. Axes have units of s/D, that is, length in terms of the number of rotor diameters, where D = 198 m

The farm layout can be rotated to have a long farm, a wide farm, and different inter-turbine distances when the wind farm is turned.

The wind farm consists of DTU 10 MW turbines, but the scaling is independent of the turbine type, as the numbers given in the plot are in rotor diameters.

For the electrical optimisation, the reference wind farm has a grid connection with 66kV inter-array grid voltage and a 220kV cable to the shore.

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The electrical layout of the TC RWP.  Thin gray lines: area 95 mm2, ampacity( ) 300 A.  Thin black lines: 150 mm2, 375 A.  Thick black lines: 500 mm2, 655 A.  Turbine identification numbers are shown, and S indicates the location of the electrical substation.

The details of the reference wind farm can be found in the public deliverable, D1.3 Reference Wind Power Plant.